Across 99 programs, the costs per abstinent case ($6,300) and per reduced drug use case ($2,400) were lowest for outpatient clients, and highest for residential ($14,900 and $6,700) and inpatient ($15,600 and $6,100) clients (Mojtabai & Zivin, 2003).  Enhanced outpatient services were more cost effective than standard services. In other words, the extra cost of enhanced services yielded a lower cost per unit improvement in outcomes (Jofre-Bonet & Sindelar, 2004; Sindelar et al., 2004; Zarkin et al., 2001a). 

In a randomized trial, the incremental cost effectiveness of methadone maintenance versus 180-day methadone detoxification was $15,967 per life-year gained (Masson et al., 2004). 

For alcohol- involved clients, studies suggest that less intensive brief interventions may be more cost effective in certain settings.  Several CEA studies of correctional treatment concluded that residential prison treatment was cost effective only if aftercare services were completed (Griffith et al., 1999; McCollister et al., 2003a, b; 2004). Griffith et al. (1999) found that cost effectiveness was greater for high-risk inmates who receive prison treatment plus aftercare.  Substance abuse treatment yields positive net economic benefits, although the Benefit-Cost Ratios (BCRs) varied widely (as low as 1.33 and as high as 39.0). The largest proportion of the economic benefits accrues from reduced crime, including incarceration and victimization costs. Other economic benefits reflect improved health and increased employment. 

A large study of treatment clients in Chicago found a BCR of 1.49 at six months posttreatment admission (Salomé et al., 2003). 

Five residential programs in Washington State had an average net economic benefit of $21,329 per client, and a BCR of 4.34 (French, Salomé, & Carney, 2002). 

A modified TC program for patients with co-occurring mental health and substance use disorders yielded substantial net benefits of $85,527 per client, and a BCR of 5.19 (French McCollister, Sacks, et al., 2002). 

Three CBAs of drug courts found net economic benefits: the BCR across six drug courts in Washington was 1.74 (Barnoski & Aos, 2003), 2.71 across three drug courts in Kentucky (Logan et al., 2004), and 2.8 in the St. Louis drug court (Loman, 2004). 

Return on investment was greatest for less intensive outpatient treatment.  The BCRs were 1.79 for the six- month residential TC program, 3.16 for an intensive four-month day treatment program, and 5.74 for a 10-week low- intensity outpatient program (Daley et al., 2004).